Remove code that was only used by navigator.connect.

third_party/WebKit/Source/core/dom/MessagePort.h

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 99 matching lines @@
 
     DECLARE_VIRTUAL_TRACE();
 
 protected:
     explicit MessagePort(ExecutionContext&);
     bool tryGetMessage(RefPtr<SerializedScriptValue>& message, OwnPtr<MessagePortChannelArray>& channels);
 
 private:
     // WebMessagePortChannelClient implementation.
     void messageAvailable() override;
-    v8::Isolate* scriptIsolate() override;
-    v8::Local<v8::Context> scriptContextForMessageConversion() override;
     void dispatchMessages();
 
     OwnPtr<WebMessagePortChannel> m_entangledChannel;
 
     bool m_started;
     bool m_closed;
 
     RefPtr<ScriptState> m_scriptStateForConversion;
 };
 
 } // namespace blink
 
 #endif // MessagePort_h